Millimeter of mercury. A millimeter of mercury is a manometric unit of pressure, formerly defined as the extra pressure generated by a column of mercury one millimetre high and now defined as precisely 7002133322387415000â 133.322387415 pascals. It is denoted by the symbol mmHg. Although not an SI unit, the millimeter of mercury is still routinely used in medicine, meteorology, aviation, and many other scientific fields. One millimeter of mercury is approximately 1 torr, which is 1/760 of standard atmospheric ...
Vitrectomy is when the eye surgeon removes the vitreous from the inside of the eye. Pars plana vitrectomy is a general term for a group of operations on the deeper part of the eye, all of which involve the removal of some or all of the vitreous â the eyeâs clear internal jelly. Pars plana vitrectomy eye surgery is sometimes done to remove eye floaters or vitreous hemorrhage inside the eyeball. In a vitrectomy, the surgeon âvacuumsâ out the normally clear, jelly-like fluid that fills the inside of the eye, the vitreous humor, with a surgical instrument called a vitrector. The vitrectomy procedure
Ciliary body. The anterior segment is the front third of the eye that includes the structures in front of the vitreous humour: the cornea, iris, ciliary body, and lens. Within the anterior segment are two fluid-filled spaces: the anterior chamber between the posterior surface of the cornea (i.e. the corneal endothelium) and the iris.